Production planning
Production planning is deciding before you start. It answers five questions: What will we make? How many? By when? With which machines and people? With which materials? The planner looks at customer orders and at the stock already in the store. The result is a schedule, a time table that says which job runs on which machine and when.
Planners also check capacity, the most a machine or line can make in a given time. If orders are more than capacity, they add shifts, add machines, or tell the customer a later date.
Production management
Production management is running the plan every day. Managers make sure materials arrive, machines are ready, workers know their jobs and the work follows the schedule. They compare what is done with what was planned. If something goes wrong, they act. A common problem is a bottleneck: the slowest step, which holds up everything after it. The whole line can only go as fast as the bottleneck. Making it faster, or adding another machine there, speeds up the whole line.
Managers also balance quality, cost and delivery time, because speeding up can hurt quality.
Production and distribution
Distribution is getting finished goods to customers. Goods are counted, packed, stored and loaded. Good planning keeps enough stock to meet orders but not so much that money and space are wasted. Delivery is planned too: which truck, which route, which day. If production is late, delivery is late, so the two must be planned together.
Try it
In the 3D, set orders to 18 and machine speed to 2. Are you late? Raise the speed until you are on time. Then think of something at home you make in steps, like a school lunch. Which step is the bottleneck?
Key formulas and definitions
- Capacity = rate per day x number of days
- Late if orders > capacity
- Days needed = orders / rate per day
- Line speed = speed of the slowest step (bottleneck)
- Plan = what + how many + by when + with what
Worked examples
1. A machine makes 8 parts a day. A customer orders 40 parts. How many days are needed?
Days = 40 / 8 = 5 days.
2. A line has three steps that make 10, 6 and 9 items per hour. How many items per hour can the whole line make? Which step is the bottleneck?
The line makes only 6 per hour, the speed of the slowest step. The step with 6 is the bottleneck.
3. You get an order for 90 chairs in 6 days. Your workshop makes 12 chairs a day. Can you finish on time? What can you do?
Capacity = 12 x 6 = 72 chairs. That is less than 90, so you will be late by 18 chairs. Add a second shift, hire help, or ask for a later date.
Common mistakes
- Planning only the machine and forgetting materials and delivery.
- Speeding up a step that is not the bottleneck; the line gets no faster.
- Making far more than the orders, which wastes money and storage.
- Making a plan and never checking progress against it.